Process of making artificial lumber.



No. 709,488. Patented Sept. 23, I902.

W. S. HUNTINGTON. PROCESS OF MAKING ARTIFICIAL LUMBER.

(Application filed Feb. 18, 1901.) (No Model.)

UNITED STATES PATENT OFFICE.

WILLIAM S. HUNTINGTON, OF NEW YORK, N. Y., ASSIGNOR TO THE COM- POSITE BOARD COMPANY, A CORPORATION OF NEW YORK.

PROCESS OF MAKING ARTIFICIAL LUMBER.

SPECIFICATION forming part of Letters Patent N 0. 709,488, dated September 23, 1902.

Application filed February 13, 1901. Serial No. 47,709. (No specimens.

To a, whom it may concern: boards in several particulars, as will herein- Be it known that I, WILLIAM S. HUNTING- after more fully appear. TON, a citizen of the United States, residing In order that the invention in such detail in the borough of Manhattan, in the city and as will enable a person skilled in the art to 55 State of New York, havediscovered anew and practice it may be fully understood, I shall useful Process of lllaking Artificial Lumber, describe the process which I have adopted of which the following is a specification, refas the best now known to me.

erence being had to the drawings accom- It will be understood thata proper wood is panying and forming a part of the same. first-ground in any of the usual ways and the 60- [O The invention or discovery which forms the desired quantity put in a beater-engine, to-

subject of my present application for Letters gether with a certain proportion of sulfite, Patent is the result of an extended series of as the long-fibered pulp digested with bisulexperiments conducted with the object of fite liquor is known in the market, together producing from wood-pulp a substitute for with the usual quantity of alum and size. 65

the finer grades of wood used in cabinet-mak- The proportion of sulfite may vary; but it is ing, the finish of cars, ships, and the like and somewhat less than is ordinarily used in the in which lightness, strength, and durability, manufacture of the better grades of paper. with a certain degree of flexibility, are of I also introduce into the beater-engine such equal importance with the capability of takmaterials as will have a tendency to impart 7o ing a high finish. l to the finished product solidity and hardness So far asIam aware no wood-pulp product, and, to the extent to which they remain, either in a substantially pure state or comgreater tenacity. The substances bestsuited bined with the usual fillers, has heretofore for this purpose I have found to be litharge, been produced in a condition to meet the ground white lead, and casein. A rigid ob- 75 practical requirements of such uses as those servance of proportions is not necessary; but

to which hard-wood veneers and the like are ,good results will be found to follow the emgenerally applied, mainly because of the imployment with five hundred pounds ofground possibility of obtaining by any known procwood of about forty pounds of sulfite, eight ess slabs or sheets of compacted pulp pospoundsof size, twelve poundsof ground white 80 3o sessingasufficient degree of hardness coupled lead, ten pounds of lit-harge, and twenty with flexibility; butthisobjectionl have sucpounds of alum, the latter being first disceeded in overcoming by a process of mauusolved in hot water. About twelve pounds facture which yields slabs, sheets, or boards of casein, which is also to be mixed in hot or in general an artificial lumber having the water, should be added after the other in 85 general appearance and the more desirable gradients named have been combined. This characteristics of natural wood, but of lighter admixture is thoroughly beaten in the engine weight and greater flexibility than the latter and then run or pumped off into a storageand free from all tendency to crack, split, tank, in whichitis allowed to stand generally check, or splinter and capable of withstandfor about thirty minutes or untilascum forms 90 4o ing the action of moisture and effects of heat on the surface. This latter being removed, without blistering. the mixture is transferred to the vats of an In carrying out myinvention the main obordinary cylinder-machine. Two or more ject is to impregnate the body of the comcylinders are used to pick up the pulp by sucpacted wood-pulp with a material or comtion and deliver it in thin layers or films on 5 pound which will impart to the body hardan endless felt belt, which in turn deposits the ness and flexibility without impairing the film onto a press-roll, on which the film or tenacity which is due to the natural matting films are wound until the accumulated conorfelting properties of the fibers, andin order volutions give the desired thickness of mato secure this result I have found it necesterial. The latter is compacted by the press r00 sary to depart from the usual processes folroll, then cut transversely, and deposited by lowedin the manufacture of papersheets and suitable means onto a carriage. The wet slabs or sheets are then hung in a dryingchamber or kiln, which should be constructed with special reference to the prevention therein of any pronounced circulation of air, in this respect differing from that class of drying-rooms or kilns in which steam-pipes are' placed overhead and the hot air forced downward by means of fans or the like. For this purpose it is merely necessary to have a compartment which can be tightly closed and to arrange the steam-pipes near the floor.

If the wet slabs or sheets produced as above described be dried without further treatment, they will not be suitable for the uses contemplated herein, mainly because of their brittleness; but by drying them in the presence of the vapor or fumes of a material which is capable of imparting hardness and flexibility to them they appear to'become impregnated with such material and to acquire these prop erties to a marked degree. This result may be secured tovarying extents and by the use of various hardening compounds; but I prefer to use as the materials for producing the said vapor or fumes litharge, bicarbonate of soda, casein, and sulfuric acid and the flour or dust of wood, applying the same in the following manner: I provide for use in the kiln any suitable receptacles, which are to be placed on the heating-pipes. In the bottom of each I place about six pounds of litharge, over which I deposit a layer of four pounds of casein. Over this I sprinkle about one pound of bicarbonate of soda and cover the whole with a layer about two inches thick of wood-dust from the sanding-machines, saturated with sulfuric acid. I then pour over the whole sufficient sulfuric acid to entirely decompose the other ingredients. The acid filtering down through the dust or flour of.

wood attacks the materials beneath, developing fumes, which fill the chamber and act upon the drying slabs or sheets, imparting thereto the peculiar hardness and flexibility which characterizes the product which I manufacture. The drying process is conducted, as above stated, in a closed or sealed chamber and at a temperature of about 120, which is maintained for about twenty-four hours. At the end of this period the dried and hardened sheets are removed and after having been trimmed or edged are sprinkled with water at points where warping or bulging has occurred and then placed under a hydraulic press and subjected to pressure to restore them to their original fiat condition. The sheets are then passed between hot calendering-rolls to surface and thoroughly free them from moisture, after which they are sanded to give them a true surface and to reduce them to the desired thickness. In this condition the sheets are useful for many purposes; but to secure the full benefit of my improvement I apply to the smoothed surfaces of two, three, or more sheets a suitable glue, such as that now commercially known as casein-glue, and unite them under pressure into composite boards or sections of any desired thickness. By the same operation I impart to the boards such forms as they are required to have in use, as head-linings for cars or the like. After this treatment and when the glue is dried and the body of the material has acquired a permanent shape or set the material is treated in the same manner as wood or veneers with fillers, varnish, or paint of any desired kind. V

In carrying out the above-described process I may employ any suitable apparatus or mechanism, the invention, broadly considered, not being limited to the use of any precise form. For purpose of illustration, how ever, I have shown a simple form of apparatus which is capable of being used for the purpose, omitting the calendering-rolls and presses, as these are such well-known devices as to require no special description.

Figure 1 is a view, partly in side elevation and partly in section, of the apparatus for forming the sheets or slabs. Fig. 2 is a view of the drying-chamber or kiln, a portion of the side wall being removed to show the interior arrangement. Fig. 3 is a perspective view of one of the finished boards or sections of material. I

A B indicate a pair of pulp-vats, within which are mounted the screen-cylinders 0, preferably having communication with a suitable suction apparatus, as is usual in such cases.

D is an endless belt of felt, which is pressed against the cylinders O by couch-rolls E to receive the layers or films of pulp taken up by the cylinders. The belt D leads to the drum or press-roll F,which receives and winds up the film until the desired thickness is obtained. Cooperating with the drum F is a wringer-roll G in adjustable bearings, which is used to express the surplus from and to compact the layers Wound on the drum.

H is a chamber capable of being tightly closed and containing a series of steam-pipes K near the floor of the same.

L designates some of the slabs or sheets as taken from drum F and shown as hung in the chamber H.

M M are the receptacles containing the hardening materials above described and placed on the pipes,so as to be heated thereby.

In Fig. 3 the slab L is shown bent to its final form.

Fromthe above description of the invention it will be seen that the presence throughout the body of felted or matted fibers of material, which impart to the compacted mass hardness and flexibility, is essential.

Some of the necessary ingredients, as explained, are incorporated with the pulp; but so much of these is removed in the beaterengine and vats by the washing action which the pulp undergoes until it is lifted out of the vats by the cylinders that resort must be had to special means for impregnating or treating the substance to impart to it the desired propvoe sc erties. The most effective method of accomplishing this is that described, and which consists in drying the sheets by heat in the presence of the vapor or fumes of the hardening materials. I have, however, found that similar results may be secured by other means, which in a broad sense I regard as the equivalent to that described. For example, I have mixed together the materials used in the receptacle in the dryingchamber and subjected them to a low heat in a closed receiver until the decomposition has taken place. This leavesa quantity of liquid,together with some sediment. If the liquid be drained off and mixed with the pulp in the vats, the sheets formed from such pulp after being dried in a closed chamber Without further treatment will be found to produce to a degree the hardness and flexibility characteristic of the prodnot of the preferred process. It will be seen, therefore, that the order of thesteps of the process in its broader aspects, and particularly in so far as the incorporation of the hardening material is concerned, is not material.

What I claim as my invention is 1. The process of making artificial lumber which consists in forming and compacting wood-pulp into moist slabs or sheets, and drying the same in a heated atmosphere charged with materials capable of hardening and imparting flexibility to the same.

2. The process of making artificial lumber, which consists in' forming and compacting wood-pulp into slabs or sheets, drying the same by heat in the vapor or fumes of materials capable of imparting hardness and flexibility tothe same, and then flattening and finishing the sheets, as set forth.

3. The process of making artificial lumber which consists in subjecting slabs or sheets of wood-pulp in a wet state to the action of heat in the presence of the vapor or fumes of materials capable of imparting hardness and flexibility to the slabs and then superposing and uniting the dry slabs by pressure, as set forth.

4. The process of making artificial lumber which consists in subjecting individual wet slabs or sheets of wood-pulp to the action of heat in the presence of materials capable of imparting hardness and flexibility to the same, then subjecting the slabs to pressure to correct the distortion incident to drying, then applying adhesive material to the slabs and superposing and uniting two or more of the same by pressure, as set forth.

5. The process of making artificial lumber, which consists in drying individual wet slabs or sheets of wood-pulp in an atmosphere charged with materials capable of imparting hardness and flexibility thereto, then subjecting the slabs to pressure to correct the distortion incident to drying, then resurfac ing the slabs to impart a smooth surface thereto, then applying an adhesive material to the surfaces, and then superposing and uniting two or more of the slabs and simultaneously imparting the desired form to the finished product by means of pressure, as set forth.

6. The process of making artificial lumber which consists in drying wet slabs or sheets of woodpulp by the action of heat in the vapor or fumes produced by sulfuric acid, litharge, casein and an alkali, as set forth.

WILLIAM S. HUNTINGTON.

Witnesses:

JOHN C. KERR, RICHARD DONOVAN. 

